A standard underground sewer line is typically made of concrete pipe sections that when originally installed were thought to have a nearly endless service life due to the low activity of the waste water being conveyed. In recent times, however, waste water has become substantially more aggressive so that such concrete pipes are subject to attack and are in fact being damaged to the point where they can leak and pollute the surrounding ground water. Replacement is an extremely onerous task entailing excavating the conduit, removing it, and installing a new line of more resistant properties, typically of a synthetic resin. The damage to the surroundings entailed in digging out and replacing a sewer line is enormous, in particular in urban settings.